1. Field of the Invention
This invention relates to frequency selective systems, and is more particularly concerned with electric wave filter apparatus with a minimum ring for a given amount of selectivity and is also concerned with a circuit that will pass a radio telegraph signal with better efficiency than noise or other interference.
2. Description of the Prior Art
In the reception of radio telegraph signals and in other like applications, it is desirable to have a selective filter which provides for a cessation of output signal almost as soon as the input signal is removed. Unless this happens in radio telegraph reception, the dots and dashes will blend into each other and be very difficult to copy.
It is common practice to design a filter to respond to a wide band of frequencies in order to prevent the filter from having an output signal after the input signal to the filter has been removed. This design technique, however, defeats the purpose of the filter.